Sleep apnea is a condition that causes you to briefly stop breathing while you are asleep.
Normally, when you sleep, the muscles of your throat relax. If there is too much tissue pressing on the outside of the throat or too little room inside of the throat, the airway can become blocked. This stops your breathing, and causes the amount of oxygen in your blood to drop. This decrease in blood oxygen causes the brain to signal the body to wake up. When you wake up, the airway opens, and you begin breathing again.
This cycle repeats and can happen as often as 50 times or more during an hour. Usually, you will not remember waking up during the night the following day, but the repeated periods of arousal caused by sleep apnea will cause you to not have a good night’s rest, and you may be drowsy the next day.